In some metal recovery processes, such as the recovery of iron from ore, products are generated which are at a high temperature and pressure. One such product is, for example, iron carbide fines at a temperature of about 1000.degree. F. in the presence of product gases at a pressure of about 50 psi. The product is delivered under high pressure from a reactor via a cyclone and requires cooling as well as pressure reduction down to atmospheric pressure.
It is accordingly an object of the present invention to provide a heat exchanger for heating or cooling a product, while at the same time effecting a pressure reduction.